2014/12/29 by Se-Hyung Cho, Jaeheon Kim, Youngjoo Yun · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Circumstellar envelope #Envelope (radar) #Maser #Stellar pulsation #Stellar, planetary, and galactic studies #Variable star #Very-long-baseline interferometry #astro-ph.SR
paper · pdf · doi:10.5303/jkas.2014.47.6.293
published in Journal of The Korean Astronomical Society 47(6), 293-302 (Korean Astronomical Society) · 10 pages
arxiv created 2014/12/29 · openalex publication_date 2014/12/31 · arxiv updated 2015/06/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Simultaneous time monitoring observations of <TEX>H2O</TEX> <TEX>616-523</TEX>, SiO J = 1-0, 2-1, 3-2, and <TEX>29SiO</TEX> <TEX>υ=0</TEX>, J = 1-0 lines are carried out in the direction of the Mira variable star TX Cam with the Korean VLBI Network single dish radio telescopes. For the first time, the <TEX>H2O</TEX> maser emission from TX Cam is detected near the stellar velocity at five epochs from April 10, 2013 (<TEX>φ=3.13</TEX>) to June 4, 2014 (<TEX>φ=3.89</TEX>) including minimum optical phases. The intensities of <TEX>H2O</TEX> masers are very weak compared to SiO masers. The variation of peak antenna temperature ratios among SiO <TEX>υ=1</TEX>, J = 1-0, J = 2-1, and J = 3-2 masers is investigated according to their phases. The shift of peak velocities of <TEX>H2O</TEX> and SiO masers with respect to the stellar velocity is also investigated according to observed optical phases. The <TEX>H2O</TEX> maser emission occurs around the stellar velocity during our monitoring interval. On the other hand, the peak velocities of SiO masers show a spread compared to the stellar velocity. The peak velocities of SiO J = 2-1, and J = 3-2 masers show a smaller spread with respect to the stellar velocity than those of SiO J = 1-0 masers. These simultaneous observations of multi-frequencies will provide a good constraint for maser pumping models and a good probe for investigating the stellar atmosphere and envelope according to their different excitation conditions.